1. Field of the Invention
This invention relates to a method and apparatus for continuously packaging batches of containers or the like by means of plastics film. The invention also relates to the pack obtained.
2. Description of the Prior Art
It is known to combine a certain number of identical containers, such as six bottles or cans, into a single pack formed from films of heat-shrinkable plastics material. Packaging apparatus for this purpose comprise a heating path the purpose of which is to heat-shrink the films which wrap the containers. In addition, because of the impossibility of uniformly distributing the hot air (and thus the temperature) which comes into contact with the wrapping, it is not possible to use very thin heat-shrinkable films because of the formation of holes in the wrapping. However, by using stretchable material much thinner films can be used, with considerable economical advantage.
To avoid on the one hand the energy consumption deriving from the use of the heating path and on the other hand the cost of the (necessarily thicker) heat-shrinkable material, it would be theoretically possible to use in packaging apparatus employing the heat-shrinkable material the known self adhesive or non-self adhesive films of elastic plastics material (such as stretchable linear polyethylene). This is however impossible in practice because of the different elasticity characteristics of the two plastics materials. To reduce both the energy consumption and the cost per pack, it is therefore necessary to devise different packaging methods and machines to be able to work with elastic plastics materials.